Apparatus for the low temperature distillation of solid carbonaceous materials



Sept. 12 1933. A. s. RAMAGE APPARATUS FOR THE LOW TEMPERATURE DISTILLATION OF SOLID CARBONACEOUS MATERIALS Filed April 8, 1929 4 Sheets-Sheet 1 Y Y 16 lg ZZ [I I] II II [I I ll I J I gvvuwntobi ,Q/zxaudsr 5. Rama "WW/TM Sept.

12, 1933. A. s. RAMAGE 1,925,455

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P A. s. RA'MAGE 5 APPARATUS FOR THE ow TEMPERATURE msunm'uon. OR'SOLID CARBONACEOUS MATERIALS Filed April 8, 192.9 4 Sheets-Sheet v 4 gnaw/M106 Patented Sept. 12, 1933 PAT. NT OFFICE APPARATUS FOR THE LOW TEMPERATURE DISTILLATION OF SOLID CARBONACEOUS MATERIALS Alexander S. Bamage, Detroit, Mich, assignor to Goals and Chemicals, Ltd., a corporation of Nevada Application April 8, 1929. Serial No. 353,557

2 Claims.

This invention relates to an apparatus for the low-temperature distillation of bituminous and other carbonaceous materials such as coal, semicoal, peat, lignite, wood and the like, the principal object of the invention being the production from such carbonaceous materials of maximum yields of valuable distillation products, including low-temperature or primary tars. A characteristic feature of the invention is that the distillation is carried out in a reducing or hydrogenating atmosphere, particularly one containing carbon monoxide or hydrogen or both, whereby a partial hydrogenation and/or reduction of the low temperature distillation products apparently occurs and the yield of aromatics is increased while the yield of tar acids is decreased in comparison with the amounts produced by the usual low-temperature. distillation processes.

In order that the further objects of the invention may be more clearly understood, it is to be noted that the distillation process of the invention generally comprises passing the carbonaceous material first through a low-temperature distillation operation and then through a gasifying operation, the hot producer gases being used to supply the heat required in the distillation operation and the water gas being additionally utilized as the reducing or hydrogenating gas above referred to. 4 A further object of the invention, therefore, is to provide for maximum utilization of the sensible heat of the air'blow gases and of the water gas produced in the process so that the distillation may take place with a minimum, or preferably with no, addition of heat from other sources.

Another object of the invention is to obtain maximum yields of combined nitrogen, e. g. ammonia, from the nitrogen content of the material treated. 4

In accordance with my invention the carbonaceous material is completely utilized in the formation of useful products, the products being primary tars, fuel gas and power, and the carbonaceous material being completely consumed to ash.

In the low temperature distillation of coals there is required to be supplied about from 400 to 700 B. t. u. per pound of coal distilled depending upon the oxygen content of the coal, while the low temperature distillation of wood involves exothermic reactions so that for each poundpf dry wood vdistilled about 200 to 300 B. t. u. are liberated. Other carbonaceous materials such as the semi-coals, peat and lignite, consume or liberate heat in amounts generally falling between the figures given for coal representing one extreme and wood representing the opposite extreme. In the distillation process to be described hereinafter the moisture content' of the material delivered to the low-temperature distilling operation is adjusted by preliminary drying and used to control the heat in the distilling operation. In the case of coal,'the distillation of which is endothermic, the coal is preliminarily dried if necessary to a practically anhydrous con- 5 dition prior to distillation. This expedient besides re'ducing the quantity of heat required to be supplied in the distilling operation has the added advantage that it avoids the dilution of the soluble products ofdistillation. In the case of wood" sawdust which may run as high as 40% moisture, preliminary drying to about 5 to 8% moisture is advisable, the residual moisture serving to absorb the heat liberated by the endothermic reactions and thus to prevent overheating of the wood in the low-temperature distillation operation.

In the accompanying drawings I have illustrated apparatus suitable for carrying out the process outlined above.

In the drawings:

Fig. 1 is a vertical section of a unit particularly suitable for the treatment of coal and other endothermic materials;

Fig. 2 is a vertical section of an apparatus comprising four units of the type shown in Fig. 1;

- Fig. 3 is a horizontal section on the line 3-3 of Fig. 2;

Fig. 4 is an elevation in partial section of an apparatus particularly adapted to the treatment of wood and the like;

Fig. 5 is a plan view of the apparatus shown in i Fig. 4; and

Fig. 6 is a vertical section of a unit which may be used for the treatment of either coal or wood.

In Figs. 1, 2, 3 and 6, the apparatus comprises a steel section 1, surmounting a firebrick section 2, which widens out into the gasifying section 3. The steel section is similar to the well-known .Herreshof furnace and is provided with revolving arms 4, mounted on a central shaft 5 and carrying staggered rakes 6. The shaft is rotated by means of gears '7 connected with a driving means of any kind. If desired the central shaft may be hollow and supplied with cooling water. The steel section may be about 9 feet high and the middle firebrick section 2 may be i to 6 feet long. It will be seen that there isthus provided in effect a water gas generator, surmounted by a shaft retort, and this in turn surmountedby an agitated shelf or baffle retort.

Pipe 8 is provided to draw off the producer gas formed during the air blowing period. The

lower part of the apparatus is provided with rotatable grates 9 and inlet pipes 10 for air or steam.

At thetop of the apparatus is a vapor line 11 and a charging conduit 12 which is fed by the conveying and drying system 13.

The retort units are advantageously grouped in batteries of four as shown in Figs. 2 and 3 where the steel retort sections of the battery are enclosed in an insulated casing 14. The enclosed chamber thus formed is advantageously provided with deflecting plates 15 and may contain a waste heat boiler as shown at 1-6 and superheaters indicated at 17. 4

In the apparatus shown in Figs. 4 and 5, the steel section of the retort is replaced by a single .horizontal retort section serving four units which are similar to sections 2 and 3 of Figs. 1, 2, 3 and 6.

The horizontal retort section shown in Figs. 4 and 5 comprises two jacketed conduits 18 and 19 through which the material is conveyed by means of helical conveyors 20. These conveyors are preferably of the type known as the cut and folded flights. This lifts up and drops the material while pushing it forward, so that every part of the material is exposed to the hot gases. and folded flight part is preferably made of a very hard steel for woods, and semi-coals, while nickel chrome or titanium iron is best for the bituminous coals to prevent abrasion.

Conduit 18 serves as a dryingsection and is heated by the gases led into its jacket 21 through pipe 22 from the jacket 23 of conduit 19.

Conduit 19 serves for the distillation of the material, the distilling vapors beings led off through pipe 24. The material coming from conduit 19 is distributed to the four retort units through pipes 25 by means of the distributing plate 26.

The material is fed into the system through hopper 27 and passes from conduit 18 to conduit 19 through hopper 28.

The operation of the above described apparatus is so carried out that the producer gas generated in section 3, while blowing with air, is allowed to pass outside of column 2, while the water gas generated when blowing with steam passes through column 2 and then through the retorts and out through pipe 11 and conveyor 13 in the apparatus of Figs. 1, 2, 3 and 6, or through condug; 519 and pipe 24. in the apparatus of Figs. 4 an In operating a battery of four units, as shown in Figs. 2 and 3, it is advantageous to adjust the periodof blowing with-air to two minutes and the period of steaming to six minutes. In this way the enclosed chamber receives a steady flow of air blow gases, which enter the chamber through pipes 8 and are deflected by deflectors 15 around the retorts. The gases pass out of the chamber through the waste heat boiler 16 and stack 29. The steam generated passes through superheaters 17 before going to the retorts.

The apparatusshown in Figs. 1 th 3 is particularly adapted to endothermic materials such as coal; the apparatus shown in Figs. 4 and 5 is more suitable.

In this apparatus for exothermic material such as wood waste the air blow gases are led to the jacket of the distilling conveyor. From the jacket of the distilling conveyor the gases are led to The cut the jacket of the drying conveyor which is adapted to reduce the moisture content of the material to the desired amount, say 5 to 8%. The gases then pass to a waste heat boiler (not shown in these figures).

When treating coal the available sensible heat of the water gas is insufficient to supply the heat necessary for the distillation of the coal, so that it is necessary to utilize some of the sensible heat of the air blow gases. When treating wood and other exothermic materials this is not necessary. It will be apparent that the heat distribution requires to be regulated in accordance with the type of material being treated.

I propose to utilize the gas, after condensing it in the usual way and scrubbing with wash oil, in gas engines with direct connected generators, utilizing the hot water from the jacket and the exhaust gases in a waste heat boiler, and the steam thus generated in a low pressure turbogenerator. In this way an average yield from the gas as high as 40% 0f the B. t. u.s as electrical power may be obtained. The average yield of gas is 42,000 cu. ft. of water gas and 8,000 cu.,

ft. of distilled gas, making a total of 50,000 cu. ft. of 348 B. t. u. gas per ton of coal. The average yield of tar oils is 30 gallons, and the average yield of ammonium sulfate is 90 lbs. per ton of coal.

In treating sawdust from pine wood it has been found preferable to retain 8% water in the material before distillation to coimteract the exothermic reaction. The products obtained calculated to one ton treated are as follows: 4 gallons methyl alcohol 100%, 360 lbs. acetic acid 28%, 44 gallons tar oils, and a total gas production of 28,154 cu. ft. of 293 B. t. u. gas.

The gases from the retort are passed in series through a dust collector, a tar separator and a condenser. The gas from the condenser is then, in the case of coal, led through an ammonia tower down which dilute sulphuric acid is trickling in the usual way, and thereafter through wash oil (scrubbing towers to extract the light spirits. In the. case of wood or sawdust the washing with dilute acid is omitted, and the condensed product is treated as usual.

When treating coal a battery of four retorts of 24" diameter and one revolution per minute will distill 12 tons of coal per day of 24 hours, and produce 600,000 cu. ft. gas of 348 B. t. u.'giving 1,000 k. w. per hour, or 1,300 H. P. per hour, 300 gallons tar oils, and 1,200 lbs. ammonia sulphate, and require about 500 lbs. water per hour or half a pound per k. w. hour. A battery of four retorts of 48" diameter will distill 50 tons of coal per day of 24 hours, giving 2,500,000 cu. ft. gas of 348 B. t. u.s, or 4,300 k. w. per hour, or 5,700 H. P. per hour, 1,250 gallons tar oils, and 5,000 lbs. ammonia sulphate, at 2 revolutions per minute. The object of condensing the products of distillation is to be able to separate the tar .ture distillation of carbonaceous materials, such as'coal, lignite, peat, wood and the like, whereinv the distillation of the materials is carried out in macaw an atmosphere of reducing or hydrogenating gases, the residue from the distillation being suicjected to a gasification operation whereby in one stage there is produced water gas to supply the reducing or hydrogenating gases for the distillation and in another stage producer gas, the sensible heat of which may be utilized in the drying and distilling of the carbonaceous materials.

The invention also includes apparatus for carrying out the above process, comprising broadly an agitated retort section associated with a -gasifying section and having means for conveying gases from the gasifying section directly to the interior of the retort section and indirectly to the exterior of the retort section.

I claim:

1. Apparatus for the low-temperature distillation of solid carbonaceous materials, comprising a mechanically rabbled shelf or baffle retort, a shaft retort, and a gas producer, said retorts and gas producer communicating for the passage of solid material and gases consecutively therethrough, and having means for the passage of gases from said gas producer into contact with the exterior of said retorts.

2. Apparatus for the low-temperature distillation of solid carbonaceous materials, comprising a mechanically rabhled shelf or baffle retort superposed upon a shaft retort, and a gas producer under said shaft retort, said retorts and gas producer communicating for the passage of solid material and gases consecutively therethrough, and having means for the passage of gasesfrom said gas producer into contact with the exterior of said retorts.

XAN'DER S. RAMAGE.

will 

